Expansion joint



Febl19, 1929.

,1'. E. M SHAFFREY 'EXPANSIVON JOINT Filed Feb. 27, 1.928

INVENTOR ATTORNEY Patented Feb. 19, 1929.

PATENT OFFICE.

THOMAS E. MGSHAFFREY, OF AKRON, OHIO.

EXPANSION Jom'r.

Application filed February 27, 1928. Serial No. 257,239.

This invention relates to new and novel improvements in expansion joints and to a new and improved method of manufacturing same.

While intended for use generally wherever it may be advantageously employed, it is particularly adapted for use in pavements, bridges and other structures composed in whole or part of concrete, cement or other material in which allowance must be made for contraction and expansion.

Briefly stated, objects of the invention are to provide an expansion strip which will be of simple, durable construction, which may be manufactured at a low cost and which will be exceedingly eflicient in use.

A further object is to provide a. cushion strip of the type above indicated which will be readily compressible when subjected to pressure by expansion of the adjacent parts of the structure in which it is used; which will possess the qualities of expanding to its normal shape to compensate for the contraction of the adjacent parts of the structure and which will retain its shape and-will not exude from the joint even when subject to great pressure or a relatively high degree of heat.

The above objects are accomplished and additional ends are attained by the novel construction, combination andarrangement of.

parts herein illustrated and described and by the new and novel process of manufacture hereinafter set forth, it being understod that the invention is subject to various adaptations and that changes and modifications may be made or resort had to substitutions which come within the scope of the claims hereunto appended.

In the drawings like numerals of reference are used to designate like parts as the same may appear in any of the several views and in which Figure 1 is a perspective view of an expansion strip constructed in accordance with this invention, the same being shown with a part cut away and illustrated in cross section.

Figure 2 is a fragmentary, perspective view very much enlarged and showing in cross section the arrangement of the various elements employed in constructing a strip in accordance with this invention. 1

In the drawings there is illustrated irregularly shaped pieces 5 and 6 of compressible material. The compressible material is screened or otherwise grated into pieces 5 and 6 of various sizes and each of the pieces 5 and 6 are entirely surrounded and bound together by a bituminous element 7. The finished strip is coated with a layer 8 of powdered material, such as marble dust, powdered lime stone, cement or other material of a similar nature. The compressible pieces 5 and 6 are preferably formed of cork which is preferably ground, granulated or otherwise broken into irregularly shaped pieces of various sizes.

In manufacturing my improved strip, I first take a quantity of ground cork and pass it through a series of screens to grade it into a plurality of sizes. While the relative sizes of the pieces of cork 5 and 6 may be varied in accordance with the structure in which the strip is to be used, the following may be given as an illustration The pieces 5 are composed of cork which will pass through a screen of 1/4 mesh and will be retained on a 1/10 mesh screen. The pieces 6 will pass through a screen of 1/10 mesh and be retained in a screen of 1/20" mesh. A quantity of powdered cork or corl: flour may also be used. The cork pieces 5 and 6 are first placed in a tumbler, mixer or other device and subjected to heat. When the cork is thoroughly heated, a quantity of finely ground lime stone or any suitable stone dust is placed in the mixer and the mixing operation is continued until all of the pieces 5 and 6 are each thoroughly coated with a layer of stone dust. The heating of the cork softens its natural binder so that each piece of cork is somewhat adhesive and the finely powdered dust readily adheres thereto. A quantity of asphaltum 7 is then heated and is added to the hot limestone covered cork pieces 5 and 6 and the tumbling operation is continued until each of the pieces of cork 5 and 6 are'thoroughly coated with the asphaltum. The resultant mixture while still warm is then pressed into sheets or strips of the shape and size desired in the particular. structure in which the strip is to be used.

While the asphaltum is still warm and adhesive the strip is coated on its four sides with a heavy layer of marble dust. The marble dust adheres to and penetrates the asphalt-um in the mixture and forms a heavy crust ens 'tirely enclosing the strip. The asphaltum 7 adjacent the surface is thus mixed with a large percentage of marble dust and forms a relatively strong shell which has heat resisting properties and permits the strip to be easily handled without adhering to .Other objec ts. As soon as the strip 8 has been coated with marble dust, it is allowed to cool and is ready for use.

While I have described the pieces 5 and 6 as being first coated with limestone dust, it is to be understood that marble dust, cement or any other suitable material may be used instead and while 1 have described the layer 8 as composed of marble dust, it is to be undgrstod that limestone dust, Portland cement or any suitable finely ground material may be used if desired.

7 Inuse', the strip isemployed in the ordinary manner to provide a joint between adjacent parts of a structure. It will be seen that'upon expansion of the adjacent parts the cork pieces 5 and 8 will be readily compressed to compensate for the expansion and that upon contraction of said parts the pieces 5 and 8 will expand thereby forming an expansion strip which will not bulge from the joint even when subject to heavy pressure. x As the outer shell 8 of the strip contains a large proportion of limestone dust or similar material, the strip will be heat resisting and will not liquely and exude from the joints during hot weather. 4

Having thus illustrated my invention and 7 described the same in detail, what I claim as said strip.

3. That method of manufacturing an expansion strip which comprises: taking pieces of cork, grading the same into a plurality of sizes; heating the cork; coating each piece while hot with stone dust; heating asphaltum; adding the hot asphaltum to the stone 'coated pieces of cork; thoroughly mixing the asphaltum and the cork until each piece of cork is completely coated with the asphaltum shaping the mass to the form desired in the finished product; then. coating the whole while hot with powdered stone.

l. That method of manufacturing an ex pansion strip which comprises: taking pieces of cork; subjecting the same to heat; adding stone dust; tumbling the cork and stone dust while the cork is hot until each separate piece of cork is completely covered with the dust; adding a hot binding medium to the dust coated cork; thoroughly mixing the cork pieces and the binding element; forming the whole into strips and while hot completely coating the strip with finely powdered stone.

in testimony whereof I have hereunto set my hand.

THOMAS MGSHAFFREY. 

